Number of n X 2 binary arrays indicating whether each 2 X 2 subblock of a larger binary array has lexicographically nondecreasing rows and columns, for some larger (n+1) X 3 binary array with rows and columns of the latter in lexicographically nondecreasing order.
A227252
Number of n X 2 binary arrays indicating whether each 2 X 2 subblock of a larger binary array has lexicographically nondecreasing rows and columns, for some larger (n+1) X 3 binary array with rows and columns of the latter in lexicographically nondecreasing order.
Terms
- a(0) =2a(1) =3a(2) =9a(3) =23a(4) =53a(5) =113a(6) =225a(7) =421a(8) =745a(9) =1255a(10) =2025a(11) =3147a(12) =4733a(13) =6917a(14) =9857a(15) =13737a(16) =18769a(17) =25195a(18) =33289a(19) =43359a(20) =55749a(21) =70841a(22) =89057a(23) =110861a(24) =136761a(25) =167311a(26) =203113a(27) =244819a(28) =293133a(29) =348813
External references
- oeis: A227252